It has been known to use three dimensional (3D) image correlation photogrammetry as a full-field, non-contact optical inspection technique to analyze strain in machine parts and dissected tissue specimens. This technique is described for example in the literature by Tyson, J., Schmidt, T. Galanulis, K. “Optical Deformation & Strain Measurement in Biomechanics”, in Biophotonics, September 2003, pages 1 to 7; and by Tyson, J., Schmidt, T., Galanulis, K., “Biomechanics Deformation and Strain measurements with 3D Image Correlation Photogrammetry”, Experimental Techniques, Vol. 26, No. 5, pages 39-42, September/October 2002 (ProQuest Science Journals). This literature describes strain testing of dissected bone, knee tendon, and ligament specimens that have been removed from a cadaver and ruptured under tensile testing, of a heart of a vivisectioned frog, and of flexed artificial muscle specimens. Known industrial applications of this measurement system are for aerospace or machine parts. These biologic specimen and industrial applications involve objects held in a fixture during testing. Measurement systems of this type are in wide use in the aerospace industry and in public universities (including the Universities of Maine, Wichita State in Kans., and Akron in Ohio), with at least 300 of them in use in Europe and 40 in the United States. For example, the United States space agency NASA used this technique to make measurements of the full Space Shuttle wing leading edge (NASA Johnson Space Flight Center & Southwest Research) as well as for External Fuel Tank (ET) foam impacts (Lockheed Martin Manned Space Systems). This technique allows for non-contact determination of 3D coordinates and 3D displacements, 3D speeds and accelerations, and plane strain tensor and plane strain rate.
An example of a commercially widely available 3D image correlation photogrammetry digital camera system is the system made by the company GOM mbh marketed under the trade designation ARAMIS system.
The preparation of the specimen with a pattern is described in the above “Biomechanics Deformation” and “Optical Deformation” articles, or alternatively in the “ARAMIS User Manual”, at pages 26-27, published by the GOM company (2005), as a high-contrast stochastic (random) pattern consisting of a sprayed-on dye penetrant developer (such as white) overlaid with a sprayed-on black spray (e.g. a matte black spray or graphite spray), for example by lightly pressing the spray button on commercially available cans of spray paint. It is also known to apply the pattern by means of a pen or a stencil/spray technique. It is known that smooth specimen surfaces are preferred. The pattern can be a regular or random pattern. It is known that it is preferred for the pattern to avoid large areas of constant brightness such as wide lines. It is known that it is preferred to avoid a shiny pattern and to prefer a pattern with a matte or dull surface.
Temporary tattoos made from dyes or inks approved for use in food or cosmetics are known for novelty purposes, as body adornment, or to mark a person's hand as having paid an admission price. These typically involve a recognized, ordered arrangement of graphic elements, or text, as known for example in U.S. Pat. Nos. 5,578,353 (Drew, III); 7,011,401 (Markey, III); 6,161,554 (Dunlap-Harris); and 6,457,585 (Huffer et al.). Some such tattoos are transferred to the person by the tattoo's having a pressure-sensitive adhesive layer. Other such tattoos are printed on a paper substrate with water soluble ink, and the paper placed in contact with the skin in the presence of moisture and the ink is transferred to the skin.
Dot patterns are known in eye color-blindness tests such as the Ishihara color chart (named after its designer Dr. Shinobu Ishihara, a professor at the University of Tokyo, who published his test in 1917) which uses colored plates having a background of dots in the middle of which is a recognizable regular pattern, differentiated by color, usually in the shape of an Arabic number or English letter, see also U.S. Pat. No. 2,937,567 (Hardy) and U.S. Pat. Appln. 2005/0213039 (Ohashi). These eye charts are usually printed on heavy stock and carefully preserved against soiling so as to be used by eye care professionals to diagnose patients.
There remains a need to determine strain fields on the skin surface of a living human interacting with a product used on the skin in a manner comfortable to the test subject person.
There remains a further need to quickly and/or conveniently apply a removable pattern to a human test subject.